Sanada et al developed equations for estimating skeletal muscle mass from ultrasound readings of muscle thickness. While MRI is the standard for measurement ultrasound is cheaper and more portable. The authors are from Tokyo Metropolitan University.
Locations for ultrasound readings (right side of the body):
(1) lateral forearm: on anterior surface 30% proximal between styloid process and radial head
(2) anterior upper arm: 60% distal between lateral humeral epicondyle and acromial process of the scapula
(3) posterior upper arm: 60% distal between lateral humeral epicondyle and acromial process of the scapula
(4) abdomen: 2-3 cm to the right of the umbilicus
(5) subscapula: 5 cm below the inferior angle of the scapula
(6) anterior thigh: midway between lateral femoral condyle and greater trochanter
(7) posterior thigh: midway between lateral femoral condyle and greater trochanter
(8) anterior lower leg: 30% proximal between lateral malleolus and lateral tibial condyle
(9) posterior lower leg: 30% proximal between lateral malleolus and lateral tibial condyle
weight of skeletal muscle in kg =
= (volume in liters) * 1.04 kg/L
Parameters:
(1) gender
(2) height in m
(3) muscle thickness in cm
skeletal muscle mass in kg =
= (A * (muscle thickness) * (height in cm)) + B
Males
|
Body Area |
Thickness |
A |
B |
|
total body |
all 9 locations |
0.641 |
-12.087 |
|
arm |
all 3 arm locations |
0.204 |
-0.517 |
|
trunk |
abdomen and subscapular |
1.303 |
1.766 |
|
thigh |
both thigh locations |
0.639 |
-2.972 |
|
lower leg |
both lower leg locations |
0.233 |
-1.347 |
where:
• The authors also reported an equation for total body skeletal muscle based on 6 locations but the components could not be found but could be the sum of the upper arms, thigh and lower legs.
Females
|
Body Area |
Thickness |
A |
B |
|
total body |
all 9 locations |
0.594 |
-11.320 |
|
arms |
all 3 arm locations |
0.132 |
0.093 |
|
trunk |
abdomen and subscapular |
0.937 |
1.794 |
|
thighs |
both thigh locations |
0.532 |
-2.638 |
|
lower legs |
both lower leg locations |
0.237 |
-1.534 |
